为了解决液体火箭发动机异种材料零件间的连接成型问题, 采用光纤激光对5 mm厚的GH4169高温合金与1Cr18Ni9Ti不锈钢在不同的焊接工艺参数下进行激光焊接正交试验, 并对焊缝进行X射线检测, 显微金相组织观察及拉伸性能测试, 检测结果表明: 激光功率为4.0 kW, 焊接速度为1.6 m/min, 离焦量为-3 mm时, 可获得内部气孔数量最少的焊缝; 激光功率取4.0～4.4 kW, 焊接速度取1.6～2.0 m/min, 离焦量取-3～-1 mm范围内的焊接参数组合时, 均可获得常温拉伸性能优于1Cr18Ni9Ti母材, 600 ℃拉伸性能与1Cr18Ni9Ti母材相近的焊缝。

In order to solve the problem of connection molding between dissimilar material parts of liquid rocket engines, the laser welding orthogonal tests were carried out on 5 mm thick GH4169 superalloy and 1Cr18Ni9Ti stainless steel under different welding parameters by fiber laser. X-ray inspection, microscopic metallographic observation and tensile test were performed on the welds. The test results show that when the laser power is 4.0 kW, the welding speed is 1.6 m/min and the defocus amount is -3 mm, the welds with the smallest number of internal pores can be obtained. When the laser power is 4.0～4.4 kW, the welding speed is 1.6～2.0 m/min, and the defocus amount is within the range of -3～-1 mm, all the welds can obtain tensile properties at room temperature better than that of 1Cr18Ni9Ti base metal, and tensile properties are similar to that of 1Cr18Ni9Ti base metal in 600 ℃.